She wandered into the bookshop and drifted along the bookshelves, occasionally touching the spine of a book or selecting a book to read the back cover. She stopped at a large display in the centre of the store and debated whether or not to purchase the hardback tome in front of her. She thought back to all the books she had already, on bursting shelves and toppling piles at home.

She reached into her bag and extracted a coin. The flip side must land on heads for her to buy the book. A few moments later she headed to the till.